Railway signaling system



1931- c. A. BROOKS ET AL 1,790,525

RAILWAY SIGNALING SYSTEM Filed June 27, 1929 INVENTORS; C,H.BI66/{$, 4 H, C. Want-036e Patented Jan. 27, 1931 UNITED STATES CHARLES A. BROOKS, F swrssvann, AND HARRY 0.,VANTASSEL', or'rrrwsnunen,

PATENT OFF CE PENNSYLVANIA, ASSIGNORS ITO THE. UNION SWiTOH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA RAILWAY SIGNALING SYSTEM Application filed me 27, 1929. Serial No. 374,068.

Our invention relates to railway signaling systems of a type involving signals controlled by track circuits.

One feature of our invention is the provision of'means for preventing'an undesirable momentary operation of a signal when a light engine or a car passes at high speed from one track section to another if the track relay for the rear section close'sbefore the track relay for the forward section opens.

We will describe one form of signaling system embodying our invention, and will then point out the novel features thereof in claims. I e

a The accompanying drawing is a diagrammatic view showing one form of signaling system embodying our invention.

Referring to the drawing, reference characters 1 and 1 designate the track rails of 3 a stretch of railway track which is divided by insulated joints2 into a plurality of track sections, only three of which sections, 'C-D,

D-E and E-F, are here shown. Each of these track sections is provided with a track 2a! circuit which is supplied with current by a nected across the'rails adjacent battery 3 connected across the rails adjacent one end, of the section, and includes a track relay designated by the reference character T with a distinguishing exponent and conthe opposite end of the section.

Located adjacent points 0 and E are signals designated by the reference characters S and S respectively, each of which gov erns eastbound traffic, that is, traffic moving toward the right as shown in the drawing.

Each of these signals is of the light type, V and, as here shown, is of whatis known as the Searchlight type signal. Each of th ese "signals comprises a member 6 mountedto oscillate and controlled by two windings 7 and 8. The member 6 carries three roundels G,

' Rand Y arranged to co-operate with an elecit is biased, roundel R is in front'of lamp 9, whereas, 'when the member 6 is swung to the left or tothe right, roundel Y or roundel G is placed in front of the lamp v9. As shown trio lamp?) in such manner that when the' 'n the drawing,'the lamp 9 is above the roun-' dels butthe lamp is placedin'this location or stop according as its roundel G, Y or It is locatedin front of its lamp 9. Opera tively connected with the member 6 of signal S are two contacts'4 and 5, which contacts are. operated in such manner that when the signal is in its. stop position contact 4. connects with its point 4 and contact 5 con nects with its point 5", when the signal is in its caution position contact 4 connects withits point 4 and contact 5 connects with its point 5, whereas when the signal is in its proceed position contact 4 connects with its point 4 and contact 5 connects with its point 5. A signal of the type thus described is disclosed and claimed in Reissue Letters Patent of the United States No. 14,940, granted to Eli J. Blake on August 31, 1920.

Associated with signal S are two relays designated by the reference characters M and P, respectively. Each of these relays is constructed to be slow-releasing so that it will not open its front contacts when signal S changes from the caution to the proceedposition or conversely. Relay M is so controlled as to be energized when track section DE isunoccupled while signal S is indiin advance ofsignal S as well as in the rear of signal S whereas when relay P is energized, signal S is controlled by. traflic conditions in the rear only of signal S Relay P is provided with a pick-up circuit which becomes energized when a train enters section D-E while signal S is indicating caution or proceed and while relay M is energized.v Relay P then continues energized while relay M is de-energized or signal S is indicating stop. WVhen a train travelsin the opposite direction, signal S 'cating caution or proceed only. Relay P is moves to its stop position, tie-energizing relay M before section D-li is occupied, and hence relay P will not become energized when the train enters section DF.

\Vinding 7 of each of the signals S and S is constantly supplied with current from a suitable source which is not shown in the drawing but the terminals of which are designated B and O. lVinding 8 of signal S is controlled by track relays T T and T and by relays M and P. Signal S is controlled by track relay T and can also be controlled by apparatus associated with the. signal next in advance of signal S sin'iil-arlytothe manner in which signal S is controlled by relays M and P which are associated with signal S.

As shown in the dray ing, each of the track sections .C-d). l)--E and E F is clear and signals ti and S are indicating proceed. Since. signal S is indicating proceed. contact l: operated by signal S connects'with its point l. With contact e-.- of signal ("3 closed and with relay T energized, relay M is energized by its circuit passing from terminal I). through contact a e. contact 10 of relay T, and the windingot relay hi to ter minal O.

Vinding 8 cl signal S is now ener ized by a circuit passing from terminal 13, throu 11 contact ll of relay M, contactlz? of relay contact 13" ot l't'ltly'l contact ll o'l relay contact 15 of relay T, winding 8 of signal S and c ntact 16 of relay to terminalO. By means of this circuit, relay P being de-energized, signal S is controlled by tratl'ic conditions in ad 'ance of signal S as well as by tratlic conditionsbetween signals S and S I will now assume tl at an eastbound train enters sections CD, tie-energizing relay T Relay T upon becoming (lo-energized opens its cont-act 15, thereby hreakingthe circuit for signal S and causing signal S to move to its stop position. i

hen the train enters section DE, deenergizing relay T relay P becomes energized by its pick-up circuit which passes Irom terminal 13. through contact l=l" of signal S contact 10 of relay T contact 17 of relay M, and the winding otrelay P to terminal (l. After a brief period. relay M, being deenergized by the opening 01 contact l0, releases its contacts 1'? and 11. After the pick-up circuit for relay l is thus opened at contact 17 of relay M. relay l. continues vucrgi led by its stick circuit which passes from terminal B, through contact l8 of relay 3 19 of relay l, and the winding o l is to terminal 0. i a the train enters section E F. dergis'iing relay T signal operated to stop position due to the opening of contact wl u breaks the circuit for winding 8 of Signal S upon being operated to it stop position, completes a second stick circuit for relay P, passing from terminal 13,

through contact l4;" of signal S contact 55" of signal S contact 1!) of relay P, and the winding of relay P to terminal 0.

hen the train leaves section DE, winding 8 of signal S is supplied witlrcurrent of reverse polarity by a circuit passing from terminal B, through contact 16 of relay P, windings of signal S contact 15 of relay T contact 14 of relay T and contact 13 of re lay P toterminal 0. Signal s now moves to the caution position. It will be noted that as already .pointed out, when relay P was deenergized winding 8 of signal S was controlled by trafiic conditions in advance of nal but that now, with relay P energized. signal S is controlled by trallic conditions between signals S and S only.

\Vhen the train moves out ot thelirst block to the right of signal S, permitting signal S to more to its caution position, signal S closes its contact 55 causing relay M to be energized by a circuit passing from terminal B, through contact 4-41 oat signal S con tact 55 of signal S contact 10 of relay T and the winding of relay lvl to terminal 0. lYith signal S now indicating caution, and with relay M energized, both stick circuits for relay 1? are open and hence relay P opens its contacts 13 and 16 and closes its contacts 13" and 16" thus again completing the normal operating circuit for signal S Signal S now moves to the proceed position.

It should be .pointed out that with apparatus comprising our invention, relay P becomes energized before an eastbound train arrives at signal S, and hence in theevent of a vehicle such as a light engine or a car passing signal S at high speed and so permitting relay T to close its contact 14 before contact 12 of relay T opens, the possibility is removed ot signal S being operated to its proceed position at thistime and displaying the proceed indication for the brief period before contact 12 of relay T opens.

Although we haveherein shown and described only one form of signaling system embodying our invention, it is understood thatvarious changes and modifications may be made therein within the scope of the apended claims without departing from the spirit and scope of our invention.

Having thus described our invention, what we claim is 1. In combination, two successive railway track blocks, a signal for the forward block controlled by tratlic conditions in said block, a signal for the rear blockresponsive to rea. of polarity of the current supplied thereto, a slow-release relay controlled by said torward block signal and by traliic conditions in said rear block, a stick relay, a pick-up circuit for said stick relay controlled by said slow-release relay and by traffic conditions in the rear of said forward block signal, a stick circuit for said stick relay controlled by said slow release relay, and means controlled by pole-changing contacts of said stick relay for supplying said rear block signal with current of normal or reverse polarity. f

In combination, two Successive sections of railway track, a signal responsive to reversals of polarity of the current supplied thereto, a slow-release relay controlled by trailic conditions in each of said sections, a stick relay, a pick-up circuit for said stick relay controlled by said slow-release relay and by trailic conditions in the rear section, a stick circuit for said stick relay controlled by said slow-release relay, and means controlled by pole-changing contacts of said stick relay for supplying said signal. with current of normal or reverse polarity. V

3. In combination, two successive sections of railway track, a signal responsive to reversals of polarity of the current supplied tliereto, a slow-release relay energized when both oi said sections are clear but de-energized when either of said sections is occupied, a stick relay, a pickup circuit for said stick relay energized when the rear section is occupied vhile a front contact of said slow-release re lay is closed, a stick OilClllt fOl said SillCkTE-r lay controlled by a ,back contact of said slow-release relay, and means torsupplying said signal with current of normal orreverse polarity according-as said stick relay is deeiiei'gized or is energized.

i. In combination, a section of railway track, a signal responsive to reversals of'polarity of the currentsupplied thereto, a slow- K relay for supplying said signal with current of normal polarity, and means controlled by a front contact of said stick relay for supplying said signal with current of reverse polarity.

5. In combination, a first and a second section of railway track, a signal responsive to, reversals of polarity of the current supplied thereto, a stick relay, a'piek-up circuit for said stick relay, means for energizing said pick-up circuit when said first section is unoccupied while said second section is occupied, a stick circuit for said stick relay, means for energiziiig said stick circuit when said second section- 15 occupied, and means controlled by said stick relay for supplying said signal with 7 current of one polarity or the other.

In testimony whereofwe .a lix our sigiiatures.

CHARLES A. BROOKS. HARRY c. vAN'rAJssEL. 

